The debate on the best way to teach children to read has long raged between rival factions, with the government making it clear that it is firmly in the pro-phonics camp. Having stoked the reading argument by introducing a phonics check for six-year-olds, ministers are now set to make primaries the arena for the next clash, this time over how to teach maths.
Under plans for revamped Sats tests, to be introduced alongside the new primary curriculum, pupils will no longer gain marks for showing their working out if they use so-called chunking and gridding techniques to find the answers to division and multiplication questions. Instead, they will be rewarded for using traditional short and long division and multiplication.
Education minister Elizabeth Truss has said that chunking and gridding are "confusing" and "time-consuming". But the announcement that certain methods will be specified in the curriculum and rewarded in key stage 2 tests has reignited the argument about how seriously the government takes its own rhetoric about teacher autonomy.
"Key stage 2 tests will be designed to reward pupils whose working shows they have used the efficient methods," said Ms Truss. "If children get the right answer, they get the marks. If they get the wrong answer but their working shows that they were using the most efficient methods, they will still be rewarded."
Her comments are the latest in support of more traditional teaching techniques and follow an announcement that calculators will be banned in KS2 Sats tests from 2014.
Chunking, also known as partial quotients, is a method of division that uses repeated subtractions (see panel). The grid method of multiplication involves expanding out the hundreds, tens and units, multiplying them separately and then adding up the results.
A 2011 Ofsted report into maths in 20 successful schools found that chunking was not popular, with feedback that the many steps involved confused pupils. But schools were keener on the grid method to introduce long multiplication, which can then be used later to multiply algebraic expressions.
Unions have expressed anger that the government is attempting to prescribe teachers' methods. Mary Bousted, general secretary of teaching union the ATL, said the move was "a gross interference in teaching and learning". She added that ministers should concentrate on taking responsibility for the education system as a whole, rather than dictating how each task was taught.
Russell Hobby, general secretary of the NAHT heads' union, said: "This government undermines its assertions of respect and promises of autonomy at every turn. Must we now also eagerly await the health minister's insights into keyhole surgery? As primary maths is improving, one might suspect the professionals have some insight into what they're doing."
The changes are due to be introduced alongside the revised primary curriculum in 2014 and in Sats tests from 2016.
Rob Eastaway, a former president of the Mathematical Association and co-author of Maths for Mums and Dads, agreed with Ms Truss that chunking was "long-winded". "I am increasingly convinced... that it leads to a greater chance of an arithmetical mistake," he said.
But he added that giving pupils marks for showing their working out with specified techniques was also an error. "You are going to get the ridiculous situation where kids are just being taught that you may get a couple of points for writing down the sum correctly, even if you don't know how to complete it."
How chunking works
The method uses repeated multiplication with numbers that children are confident with, such as 10 and 5.
For example, if we take 597[s5]22, we know that 10x22=220, so we start by deducting 220 from 597: 597-220=377.
We still have more than 220 left over so we repeat this step: 377-220=157.
We now have 157 left over. We know that 5x22=110, so we deduct that: 157-110=47.
We now have 47 left over. We know that 2x22=44. So we do the final step: 47-44=3.
Now we add the multipliers up: 10+10+5+2=27 remainder 3.